let resize = function() {
	let designWidth = 1920 //默认设计图尺寸 1920*1080
	let wW = document.documentElement.clientWidth // 窗口宽度
	let html = document.documentElement
	let rem = (wW * 10) / designWidth
	html.style.fontSize = rem + 'px'
}

resize() // 初始化

window.addEventListener('resize', resize, false) // 绑定到窗口事件中
